Glue applicator for lumber stock



June 29, 1954 Filed Dec. 7, 1948 F. A. NICHOLSON GLUE APPLICATOR FOR LUMBER STOCK 5 Sheets-Sheet 1 (Ittorneg w June 29, 1954 A, NICHOLSON 2,582,254

GLUE APPLICATOR FOR LUMBER STOCK Filed Dec. 7, 1948 5 Sheets-Sheet 2 1 48 4 e4 6 5 I I I -ii -1 l I I m. 42 46 4F 5 @047 43 0| '1 V [I 26 1 L 52 as 48 attorney 3":

June 29, 1954 Filed Dec. 7, 1948 F. A. NICHOLSON GLUE APPLICATOR FOR LUMBER STOCK 5 Sheets-Sheet 3 so/V Pkg/e52 ICK A. MCI/0L summer June 29, 1954 F. A. NICHOLSON 2,632,254

GLUE APPLICATOR FOR LUMBER STOCK Filed Dec. 7, 1948 5 Sheets-Sheet 4 /2-50ER/C/ 4. Ma /0110 4; m

attorneys J1me 1954 F. A. NICHOLSON 2,682,254

GLUE APPLICATOR FOR LUMBER STOCK Filed Dec. 7, 1948 5 Sheets-Sheet s I TQE'DEBICK nventm' (Ittornegs Patented June 29, 1954 UNITED Y STATES PATENT F F ICE GLUE APPLICATOR FOR LUMBER STOCK Frederick-A. Nicholson, Seattle, Wash.

Application December 7, 1948, Serial No. 63,889

7' Claims. 1

This invention relates. to a.- glueapplicator.

More particularly, this invention. relates to 'an edge .glue applicator designed particularly to apply a glue or adhesive to a patterned surface, such as the. pattern employed when. pieces of lumber stock have mating surfaces on "the end portion of each piecefiof the stock and the pieces of stock are to be endspliced.

. Any suitable adhesive may beap'plied by "the device of this invention, and as illustrations but not as limitations, the types ofadheSiVes'commonly employed will be .thermosetting adhesives,

thermo-plasticadhesives, and adhesives which are set by the evaporation of volatilestherefrom.

As this invention is. particularly applicable to applying an. adhesive to the end portions Oflurnber stock which are to be end spliced and glued together, the invention is generally illustrated. in connection with a conventional end splicer (a device to cut the desired pattern onthe end of pieces of lumber stock) and parts of such a. conventional end splicerare generallyindicated in Fig. l of'the drawings.

"The aforementioned. general objects of.my.invention, together with others inherentin the same, are attained by the device. illustrated .in the accompanying drawings, throughout which like reference numerals indicate" like parts:

Figure 1 is a view in elevation illustrating an application of the present invention to and asa part of an end splicing device forlumber;

lFig. 2 is a detached'elevational view enlarger scale than Fig. 1 of a. glue applicator. of.this invention;

'Fig..'3 is an exploded elevationalview bfithe construction'shown in Fig- 2 of the'ldrawings;

Fig. 4. is a fragmentary perspective view showing two fragments of pieces of stockeach having a patterned endportionto form a type; of splice joint in connection-with whichgluemaybe .applied. inmaccordance with the construction. of this invention;

. Fig. 5. is a. view. similar to Fig.- lshowing the pieces partially urged together;

Fig. 6 is a view partially in plan. andvpartially in section taken-substantially onbroken line- 6-6 of Fig. 2;

Fig. 7 isa-detachedview of coupling member which may be employed .inthisinvention; .and

Fig-.' 8 is a viewin plan with parts broken. away showing a portion of the assembly-illustrated in Fig. 2 of the. drawings-and adjustablesupporting means therefor.

Referring. to said Fig. l of the drawings, the end splicer. is. provided with. a. framework 8 for supporting variousparts. l'The conveyorme'chanism for conveying. pieces .of stock,.. such as 2 x- 4'5, comprises a deck 9 .andtravelingcleats.or lugs It protruding 'therethrough. ,Thestockis moved transversely of its length .by. said. traveling cleats'ltl iand...underLholdMownameans -A motor I2" functions as a prime mover fordrivdrawings.

:2 ing a cut-off or trim saw and sawdust is removed by a conduit i3. A motor [4 drives an edge cutting cutter head which is enclosed within the housing i5 and material removed by the cutter .head is driven off through a conduit I6. "The cut- "The subject-matter of this invention is indicated generally by I? in Fig. l and the parts'8 to 16 inclusive thus illustrate one form of a traveling conveyor on which are provided pieces of lumber stock It and [9 '(Figs. 4 and 5) which are travel- .ing transversely of their length and-with a pattern on an end portion to which a film of adhesive is to be applied.

Referring now toFigs. Zand 3, some of the parts of a device embodying this invention are shown in assembled relation in Fig. 2 and in exploded relation inFig. 3. The said parts shown in" Figs. 2 and 3 are removed from the glue pct 20 and shield or cover" 53 which are shown in Fig. 1. A If a 'thermo-plastic or heated type of glue isemployed, then the glue pot or housing'QS will be appropriately insulated to more readily maintain desired temperatures. Glue maybe pumped upwardly from the .glue potZil by means of the screw type'pump employing screw 2! within tubular member 22. ApIurality of openings 23 (see Figs. 3 and 6) are provided in the coupling portion 34 of the doctor roll 24 and are preferably uniformly. spaced around the periphery thereof. These openings 23 are .shown in elevationin Fig. 3 andqappear in the sectional. parts of Fig. 6. Glue that is pumpedby screw 2 l and out through openings 23 rests on the top of the doctor roll 24 and is caused to move outwardly and downwardly on the surface of the doctor roll 24 by auxiliary scraper 25 (see detached in Fig. 3 and inscraping positionv in Fig. 6). The doctor roll 24 has a pattern thereon which will match the pattern at the .end. of the lumber-stock such as that indicated :in-Figs. 4 and 5 of thedrawings. The doctor roll 24. is driven by meanshereinafter described. and meshes with a glue applicator roll 26. Glueapplicator roll 26v is also a driven'roll and is :relativelyimovabletoward and away :from the do'ctor r011 24' by mounting the doctor rollM for'rnovement toward and away from the-glue applicator roll 26. *As the glueisscraped off. the top surface of doctor roll 24, it moves downwardly following theperiphery of the doctor'roll 24. The glue applied on applicator roll 26" depends upon thedi'stance separating the "doctor roll 24 and the glue applicator roll 26. In other words, the closer the rolls are together, the less glue film will be deposited on the glue applicator roll 26. The peripheral design of the glue applicator roll 26 is such as will mesh with the pattern on the end of the material to which glue is to be applied, and at the same time the patterns of the peripheral surfaces of the doctor roll 24 and the glue applicator roll 26 match.

By means hereinafter described, the glue applicator roll 26 is movable toward and away from the work to provide a desired spacing between the work and the peripheral surface of the glue applicator roll 26. The larger the opening therebetween, the more glue that can be deposited on the work. If the adjustment between the doctor roll '24 and the glue applicator roll 26 is such that large amounts of glue are being deposited on the glue applicator roll 26, then appropriate adjustment should be made between the glue applicator r011 26 and the work to permit the deposit of such glue. If the glue applicator roll 26 is too close to the work, it tends to squeeze glue away from the surface on which glue is to be deposited or tends to squeeze the glue away from the surface and into the wood, either of which is undesirable. When smaller amounts of glue are being fed on to the peripheral surface of the glue applicator roll 26, then an appropriate adjustment should be made between the work and the peripheral surface of the glue applicator roll 26 to ensure that this smaller amount of glue is appropriately spread. The means for adjusting the glue applicator roll 26 toward and away from the work may be in the form of a construction whereby the assembly, mounting roll 26, is movable toward and away from the work.

As most glues have a predetermined pot life, it is necessary to provide a structure which can be readily assembled or dis-assembled to provide for periodic cleaning of the various parts such as is incidental to shutting down after completion of a shift with a lay-off period occurring before the next shift. In my invention, I have provided a construction which is extremely practical in that it provides for ready assembly and dis-assembly and .thus details of my invention are likewise important.

The screw 2| is provided with a flange 21 toward the upper end thereof and said flange 27 carries a tongue 28. The tongue 28 can be moved to interfit with the groove 29 in the face of coupling 3|]. The coupling 30 is a driven coupling and has a peripheral groove 3| therein. Also the coupling 3|! is provided with two diametrically opposed grooves 32 which are aligned with the end portions of the groove 29. The doctor roll 24 carries button head screws 33 in the coupling portion 34 thereof. Also the said coupling portion 34 carries set screw 35. In order to connect the screw 2| and the doctor roll 24 to coupling 30, the tongue 28' is inserted into the groove 29. As the coupling portion 34 is moved upwardly, the heads of button head screws 33 will pass through the end portion of groove 29 and through the grooves 32 and into the groove 36 in the top portion of coupling 33 (see also Fig. '7). As the shanks of button head screws 33 are external of the periphery of coupling 30, the coupling portion 34 may be angularly moved and the button head screws 33 will move in groove 36 and be supported by the flange forming said groove 36 to prevent the coupling portion 34 from dropping. The groove 36 is only a portion of the distance around coupling 3'0 and thus stop portions 31 can thrust against the heads of button head screws 33. Then if set screw 35 is tightened, the inner end portion thereof will nest in the groove 3| and the parts will be held in this position. The coupling portion 34 carries a flange which fits against and supports the flange 21 and thus the flange 21 is limited in its downward movement relative to coupling portion 34 and the tubular member 22, but the screw 2| can be moved upwardly when the parts are in dis-assembled relation to remove said screw 2| from the tubular member 22. As the coupling 30 is a driven member, its rotating motion will be imparted to the screw 2| via groove 29 and tongue 28 and to the doctor roll 24 via button head screws 33 and stop portions 31 of the groove 36.

In order to remove screw 2| and tubular member 22, it is only necessary to loosen set screw 35, angularly move coupling portion 34 until the button head screws 33 are aligned with grooves 32, and the outer portions of groove 29 and said two parts may be lowered, providing of course that provision is made to release glue applicator roll 26 by means hereinafter discussed, and also to release the bracket 38 which supports the tubular member 22. The doctor roll 24 is mounted for rotary movement about the tubular member 22, and the doctor roll 24 can be moved longitudinally of the tube 22. However, once the coupling portion 34 is secured to the coupling 3|), then the doctor roll 24 is carried by such coupling 36 and at the same time rotates about the tubular member 22.

As a means of adjustably suspending bracket 38 from gear box 39, I provide a bracket 40 having preferably a depending arcuate bracket 4| (see Figs. 2, 3, and 6) with a machined surface thereon. The bracket 4| carries bolt 42 having a wing nut 43 threaded thereon. Bolt 42 slidingly receives a groove 44 (see Fig. 6) in bracket 38 so that upon loosening of the wing nut 43 the bracket 38 is slidable relative to the arcuate bracket 4|, and upon tightening of the wing nut 43 a desired adjusted relation between the brackets 38 and 4| obtains.

It is desired that a scraper be provided for the peripheral surface of the glue applicator roll 26 after the said applicator roll has contacted the surface of the wood on which glue is to be applied. If sawdust should be picked up on the glue applicator roll 26, such as a scraper will remove the same so that it will not accumulate in sharp corners on the periphery of the glue applicator roll 26, and the sawdust, if any, can be delivered back to the glue pot 20 and there screened out or permitted to settle if desired. Such a scraper, as scraper 45, can be supported by the bracket 4|. The bracket 4| is shown as having four cap screws 46 threaded therein (see Fig. 2) and the scraper 45 is provided with matching key hole slots 41 so that the scraper 45 can be inserted in place, after the cap screws 4% have been loosened, and then the scraper 45 held in any desired adjusted position by tightening the cap screws 46. The scraper portion of the scraper 45 is provided with a pattern matching the peripheral pattern of the glue applicator roll 26. Also the scraper 45 forms a convenient and suitably located support for the auxiliary scraper 25 which scrapes the top surface of the doctor roll 24.

The glue applicator roll 26 is supported on driven shaft 48 and suitable gear ratio obtains sausage yEbetxveenctheiidrivemshafta48azand:the driven .cou- ."plin i:3ll-:x so: .that theigluea applicator rollri fizand -thei doctor-01124 have thesame; peripheral-speed. i'1he .;driyen-.-shaftz 48,:is: provided; with: a" key. as 1which-:is-- slidable;:into;v asuitablegrooverini the =;hul: 50;;ohthe applicatorrollflfi. .The shaft iiicis ,:-provided -=-with1threaded;portions;.onrwhich: are :mounted: nutsrii l andvfiz. .Uponrangulara-moverment oiwthernuti- 5 I astop ;is cprovided 5170.3d8t6famine the: vertical positionrrofl the: glue; applicator ..r,ol1 5 a and 5 Upon. tightening" IOfr nutxfiZ {thfiiQlUE applicatorrrollm'l 6. -is.-:held in apdesired radi usted @elevational position.

uIm-ordertoremovethe partswhichwill be 'constacted by the glueand -irom which it;is:-desir,ed 'tOi remover all; glue; the bracket; Afi-cambe re- :moved. afterlcosening-cap screws-.46. Then; the ,bracket 38 ..a-nd [the tubular :member: 2 2 can 1 be u-removed uponvloosenipg wingnut .43. iThen nut .52-.can' :be unscrewediand thereafter the set'screw .35; is e-loosened. Then uponivangular 1.- movement ofithacoupling portion -3 4., the buttoniheadscrews 33 can be moved=until.their .heaclzportionsreg- .isterwith-grooves:32. Thenaas'the heads: of button ahead screws: .33 .will -.r egister with-"both grooves .32 and the end portions: :of groove 2 9,- the doctor roll 24.-- and the glueiapplicator-roll 26:.can Fbeimoved-downwardly together. Thus iupon re- .movalof theseparts, they can be readily treated with .suitable cleaning. solutionsor cleaning apparatus and the; parts .willhave-any glue residue removed therefrom.

Refierringlnowato Eig.- l of' the. drawings, the glue .pOt-ZQ is preferablyaprovided-witha protective shield 53. in order-to.- prevent sawdust or the alike enteringrtheiglueipot r20. .-.-A-cov-ered fillspout 54 tor. the glue pot. 2511s. at .any suitable location. The :sheave 55 maybe a'separatelya driven sheave but..-is preferably;- a, sheave connected with the conveyor mechanism as by. sheave 56 and V-belt 'means 5'1.

Refierringnow to; Fig. v8-,=awhichsis= a plan view .lookingrdirectly -.downwar dly .intoithe. glue pot and having portions brokenaway, the driven sheave fidiskeyedxon cross shaft 58. vThe cross eshaftfiihrigidly carriesvworms 59. and B0. Worm .Wzmesheswith.wormwheelfil whichis fixed on shaft..62. Shaft .62 is the vshaft supporting: the coupling. .tfisdriving doctor roll 24. means 3.15. pivoted by pivot means 64. to the. gearcase 39. .A linkor. eyebolt. B6 hasone .end, portion .pivotedto. the. arm means 63 .and .said link .65 extends. outwardly. through the. gear case. .39 and .throughthegluepot and ismounted for rela- .tive..sliding movement through openings in .said gear .caseand saidglue pot. As a meansto pro- ,videeadjustableslongitudinal movement of the .linlcfifi and in turn. angularmovement of the shaft.621aboutpivotmeans 64, I haveindicateda compression spring 6'! mountedon said link 66 and abutting the. gear .case. 39 and..a-suitable flange. onthelinklifi. Thus the said spring. 5'!" tends to angularlymove the arm means 63 in clockwise direction as viewed in'Fig; 8 or toward the left as viewed in said figure. The outer portion of the link 66 is threaded and anadjusting wheel=i38 is threaded onv saidjthreaded portion. of the link 56. Thus upon loosening .of thewheel .58, the spring "61 willangularlymove the! arm.means 63 in a clockwise direction as viewedin- Fig. 8, and uponutighteningr of-said wheel68, the arm means 63-willsbe moved in the otherrjdirection, as a countere-clockwise'direction :asvievved in Fig. 8.

. =A piece'ofmaterial to-ha.ve glue applied ;ori its end portionr is .in'dicatedi-by sthe ifragment :udzin "Fig: 8 and the piece is movedin .thetdirectionixif :the. arrow by conveyor-means:andapast. the glue applicator roll-26, a fragment-mfuwhichsis -also shown in said Fig. 8. ;Thus; as thesh'aft 52. and

.the doctor roll 24 carrieditheiiebmmovezctoward the left: as viewed in; Fig; 8, the orifice: between the doctor roll '24 and;thez,gluea applicator roll-$26 iszdecreased. and :thei'same -is' increased' byrmovementgof .the shaft 62 in: the opposite;- direction.

The worm" wheel-z. 6 I. maypsmove with; rthe warm means 63 a sufficientamount fonadjusting purposes without .unmeshing wormwheeltlagand -Worm Gil-carried-by cross shaft 58 meshes with :a worm :wheel 10 andworm-wheel is mounted on. shaft: 48 which. shaft carries glue applicator roll 26. As; glue applicator roll 26 is of-aazllarger diameter than doctor roll 24; and as it-- -is. .desired to have the same-peripheral speed for the;;do.ctor

roll 24 and theglue applicatorroll 26; .a' suitab1e gear ratio is selected between the wormsdia and .60 and "their driven worm'wheels [it-and l0.

Theglue pot :2 0 isfixedto the main framework 8. The: glue pot-:20 may -be open.- at:its itopuas the shield 53 is provided. The:gearnboxiwiand the parts connected :therewith which: areusubstantially .all' shown in-Fig; 3 'of theidra'wingsiare mounted for: movement :as: arunitwithathe gear box 39. Preferably a readily.adiusta'blemassembly is providedwhichamay: includearmtmeans: -ll pivoted by spaced pivot.;means 1'12 tolrthe glue-pot '20 and by spaced. pivot' means 113. to zaxcross; arm

14. We thus have a parallelogramandthearms H will "remain parallel: as: theyv aresangularly moved and the crosszarm l tmay. bei'imoved'lcto the right or to;the-left' as'viewedin- Eigza 8;.and it will remain parallel to. the adjacentrwallaof the glue pot 26. A hook-like flange 15. is carried by the gear case (iii-and is detachablysecureduto a ledge on the cross arml i as by-set-rscrewxand nut means.- 16. Upon loosening:oiitheisetuscrew and nut means I6, the'gear 0&8815139 ..and-..parts carried thereby can be-readily removed asa unit.

In order to provide for movement oflithe gear case 39 toward and away from piece 69 and-sin turnzmovement of the glueapplicator rolltjzfi toward and away from saidpiece; a link-or eyebolt 11 is pivotedbythe pivot means 13 to' one of the arms H. The compression spring-:lBris carried by said link H and has its 'endsabutted against the arms H and a bracket 19 carried-by the glue pot 20. 'The outer endportion of the link '11 threadedly carries whe'el'80. Upon anguilar movement of lithe: wheel1i80 i in one direction,

-:the: spring -1 81 urges ithesgear case-"39 and in turn the parts carried thereby, as glue applicator r 011 .26,'-:toward a piece 69 and 'angularimovementzof the wheelz Bll .in the other direction causes :said glue applic'atorroll 26- t0 be withdrawn away from thework 69.

=In order to' -get' adesiredspreadof glue on*a surfacathe wheel-6M5 adjusted so that a desired orificeis provided between-thedoctor roll 24 and .the 'glue: applicator roll" 26. Regardless of'the amount of. glue that is. being pumped by the screw 2 l,";the amount .of,glue.whichv will. be delivered onto ,the, peripheryoijthe glue. applicator roll .26 .dep.ends..-upon.this adjustedorifice. .excess over the. amount. determined {by the a orifice will simply flow down and be returned to the glue pot. 2.0. =Obviously; 'thegglue-potrshould have a suflicient open-toptowrecieive such returningrglue. After .arruadjustment 1haszubzeemrmadexto:idetermine the glue to be applied on a glue applicator roll 26 and in turn to the piece 69, then the wheel 80 should be adjusted so that the glue is not being squeezed off by contact between the glue applicator roll 26 and the surface of the piece 69 which is being coated with glue. Too small an opening between the surface of the piece 69 and the glue applicator roll 26, tends to squeeze glue off of the glue applicator roll 26 so it cannot be applied to the wood, and further tends to compress the glue into the wood and away from a desired glue line.

After two surfaces have had their end portions coated with glue, as is illustrated by pieces 18 and [9 in Fig. 5, then the pieces can be urged endwise together and caused to remain in such position until the glue has set or has been cured.

Obviously changes may be made in the forms, dimensions, and arrangement of the parts of my invention, the above setting forth only a preferred form of embodiment thereof.

I claim:

1. A glue applicator device comprising a driven glue doctor roll mounted on a vertical shaft; a driven glue applicator roll mounted on a vertical shaft, the peripheries of said two rolls being positioned in close glue spreading controlling proximity whereby the degree of opening between said rolls determines the glue spread; glue delivery means for the top surface of said glue doctor roll; and scraper means scraping glue off of said top surface and permitting the same to flow downwardly over the peripheral surface of the glue doctor roll, whereby it will be removed from said doctor roll and deposited on the applicator roll and may be applied on the surface of material relatively passing in close proximity to the periphery of the applicator roll.

2. A glue applicator device comprising a driven glue doctor roll mounted on a vertical shaft; a driven glue applicator roll mounted on a vertical shaft, the peripheries of said two rolls being positioned in close glue spreading controlling proximity whereby the degree of opening between said rolls determines the glue spread; means to deliver glue downwardly over the peripheral surface of the glue doctor roll; an object transferring means on which object glue is to be applied said means being located in close proximity to the periphery of the glue applicator roll; and scraper means for said glue applicator roll contacting a portion of the periphery of the same which is relatively past said object on which glue is being applied.

3. A glue applicator device comprising a driven cross shaft; longitudinally spaced first and second worm and worm wheel means operatively connected with said cross shaft, said first and second worm and Worm wheel means being relatively adjustable toward and away from each other; a first vertical shaft connected with said first worm and worm wheel means; a driven glue doctor roll mounted on said first vertical shaft; a second driven vertical shaft connected with said second worm and worm wheel means; a driven glue applicator roll mounted on said second vertical shaft, the peripheries of said two rolls being positioned in close proximity to each other whereby a glue spread controlling opening between said rolls is provided, and downwardly glue delivering means for the peripheral surface of the glue doctor roll.

4. A glue applicator device comprising a gear case; a driven cross shaft supported by said gear case; longitudinally spaced first and second worm and worm wheel means operatively connected with said cross shaft, said first and second worm and worm wheel means being relatively adjustable toward and away from each other; a first vertical shaft connected with said first worm and worm wheel means and supported by said gear case; a driven glue doctor roll mounted on said first vertical shaft; a second driven vertical shaft connected with said second worm and worm wheel means and supported by said gear case; a driven glue applicator roll mounted on said second vertical shaft, the peripheries of said two rolls being positioned in close proximity to each other whereby a glue spread controlling opening between said rolls is provided; downwardly glue delivering means for the peripheral surface of the glue doctor roll; an object transferring means on which object glue is to be applied said means being located in close proximity to the periphery of the glue applicator roll; and means relatively moving said gear case and, in turn, said glue applicator roll relatively toward and away from the object on which glue is to be applied.

5. The combination of claim 4 wherein adjusting means operable externally of said gear case move said first and second worm and worm wheel means relatively toward and away from each other and wherein adjusting means operable externally of said gear case move said gear case and, in turn, said glue applicator roll relatively toward and away from the object on which glue is to be applied.

6. In a glue applicator device a housing; a gear case; a cross shaft mounted in said casing; a first and second worm mounted on said shaft; a rocker pivotal mounting means mounting said gear casing on said housing; means connected to said rocker pivotal mounting means providing a forward and back movement for said casing; a first and second shaft mounting worm wheels which wheels engage said worms of said cross shaft, one of said shafts and its worm wheel being pivotally mounted on said gear casing; means connected to said pivotally mounted worm wheel whereby said shaft may be relatively moved with respect to said other shaft; a doctor roll mounted on said pivotally mounted shaft; and a glue applicator roll mounted on said other shaft.

7. In a glue applicator device comprising a housing; a gear casing mounted on said housing; a glue applicator roll rotatably mounted in said casing having a peripheral design matching the pattern of the material to which glue is to be applied; a bracket mounted on said casing; a scraper mounted on said bracket having edge pattern matching the peripheral pattern of said applicator roll and intermeshing with said peripheral portion of the applicator roll whereby sawdust and shavings are removed from the interior portions of the pattern of said applicator roll; and an auxiliary scraper mounted on the edge of said first mentioned scraper in a selected proximity to the end surface of the doctor roll.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 320,816 Rabbe June 23, 1835 962,619 Buffelen June 28, 1910 1,191,537 Schall July 18, 1916 1,744,502 Boulton Sept. 2, 1930 2,140,470 Daneke Dec. 13, 1938 2,436,091 Bolling Feb. 17, 1948 2,537,279 Quick Jan. 9, 1951 

